In the instant specification and claims, the process of installing or including electrical energy augmentation of an internal combustion powered vehicle is referred to as “hybridization”. Vehicles thusly augmented will be referred to as “hybridized.” Further, in the instant specification and claims, the terms “modify,” “sophistication,” and forms thereof exclude such simple and inexpensive processes as drilling holes in extant elements merely to provide anchor points to interface components or to bracket or attach elements to extant components or to run wires. Where used, the term “conventional” indicates an internal combustion engine or vehicle driven thereby.
In this document, the term “motor-generator” is used to describe a transducer that can function as either an electric motor or a generator, converting electrical power to or from mechanical power, the term transducer describing any device that converts one type of energy to another type of energy.
It has long been known that internal combustion engines operate most efficiently within a narrow range of powers or speeds. However, in normal use, an automobile must climb and descend hills, stop and start, accelerate and brake, or cruise at high speeds on highways. These impose a wide range of power and speed demands on the power plant.
Thus, the internal combustion engine powering such a vehicle often will not be operating within its most efficient parameters. In fact, in the severe stop-and-go situations in which most driving is accomplished, its efficiency is generally quite low. Therefore, alternate drive systems and power sources to increase efficiency are increasingly sought.
One such effective system, popularly known as a “hybrid,” involves combining an electric motor with an internal combustion engine in such a manner as to allow back-and-forth power augmentation and trade-off, permitting the more efficient and effective of the two to provide propulsion within its best operating range as speed and power demands are made and relaxed. This permits, for example, the electric motor to augment the internal combustion engine to prevent it from having to operate above its preferred power level. In example, when the vehicle must accelerate from a stop to particular speed, the electric motor, which characteristically provides high torque, even at low speeds, is engaged to such degree that the internal combustion engine need not exceed its optimal power output. Also, while at cruise speeds, when acceleration is required, the internal combustion engine may continue to run at its preferred power level while the electric motor adds the required extra power.
The hybrid may also comprise means to convert the electric motor to an electric energy generator when the vehicle is braking or traveling downhill. Employed thus, momentum of the vehicle, and, indirectly, energy from the internal combustion engine, may be used to recharge the battery, cell, or other energy storage device, thereby literally recycling energy that would otherwise be lost. The hybrid may also have a means to recharge the battery, cell, or other energy storage device by plugging it into an electric power grid. Most recharging could be done at night, during non-peak power demand hours thusly using cheaper, low demand electricity.
In addition, many other benefits, both economic and ecological, well known to those well versed in the art, may accrue due to hybridization of motor vehicles. However, up until now, the high cost to end users of implementing this art has prevented wide scale adoption. Typically, a hybrid vehicle is designed and manufactured, as a new vehicle from the very beginning, because its manufacture requires inclusion of additional elements. Because the traditional elements of exclusively internal combustion vehicles configurations must be redesigned and specially manufactured to accommodate the additional hybridizing elements, economy of scale may not be achieved.
Further, even if a new hybrid vehicle could be brought to end users at a competitive price, market penetration would be very slow due to the hundreds of millions of conventional vehicles already on the road world-wide, the abandonment of which could not be effected without serious economic disadvantage.
With this in mind, various previous technologies have been proposed to convert extant gasoline powered vehicles to hybrid electrical units. The envisioned solutions typically require placement of one or more electric motors in mechanical communication with the wheels of a given vehicle. These motors are generally tied to an electrical storage battery and a controller similar to the one used in new design-built hybrid vehicles. Such solutions, however, continue to pose significant cost obstacles. The greatest challenge they present is to design an affordable and efficient method for installing the electric motor drive without also re-designing and replacing vast numbers of components already in use.
Typically, the proposed means of meeting this challenge requires replacement or substantial modification of the existing wheel structure, including the wheel bearings and brakes. Because of this replacement, other engineering issues and obstacles arise, such as the location, design and coordination of the electric motors as well as the addition of significant un-sprung (and therefore, excess) weight to the suspension system. These expenses multiply quickly and become cost prohibitive.